21204172454 has 32 divisors (see below), whose sum is σ = 34604698176. Its totient is φ = 9703895040.

The previous prime is 21204172447. The next prime is 21204172477. The reversal of 21204172454 is 45427140212.

21204172454 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 21204172454.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4112342 + ... + 4117494.

It is an arithmetic number, because the mean of its divisors is an integer number (1081396818).

Almost surely, 2^21204172454 is an apocalyptic number.

21204172454 is a deficient number, since it is larger than the sum of its proper divisors (13400525722).

21204172454 is a wasteful number, since it uses less digits than its factorization.

21204172454 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8480.

The product of its (nonzero) digits is 17920, while the sum is 32.

The spelling of 21204172454 in words is "twenty-one billion, two hundred four million, one hundred seventy-two thousand, four hundred fifty-four".